The Analytical Core is a central resourse composed of three laboratories which facilitate the development and application of modern analytical methods to solve key problems encountered by the components of the Superfund Program. The first laboratory is the Superfund Analytical Laboratory which provides a range of instrument services relying heavily on mass spectrometry and chromatography. The second is the Accelerator Mass Spectrometry Facility with a new sample preparation laboratory in Davis and 2 AMS instruments at LLNL for ultra trace analysis of 14C and 36C1 as heavy isotopes. The third is the Molecular Structure Facility (MSF) which provides service for fee in the area of protein and nucleic acid chemistry. The Superfund Analytical Laboratory provides a wide range of analytical services for both small molecule and (in collaboration with MSF) for protein analysis. The analytical capability supporting both proteomics and metabolomics of the 'omics core 5'is located here. The core provides walk up instrumentation as well as service and research collaboration to the projects. It advances analytical technology for example by developing robotic sample clean up procedures, immunoaffinity chromatography and 'lab on a valve'approaches to sample preparation. It carries out bioassay driven fractionation of hazardous mixtures in collaboration with the projects and provides education for Superfund scientists in analytical chemistry. The LLNL component provides access to a variety of advanced instruments but will focus on the sub attomole (i.e. 10[-8]) sensitivity of Accelerator Mass Spectrometry (AMS) in support of a variety of projects using both 14C and 36C1 analysis. This technique for example for the first time allows monitoring of human metabolism of hazardous chemicals at environmentally realistic levels. Core scentists will educate Superfund researchers in the use and value of a full array of analytical techniques.